Extensible and retractible beam



United States Patent 3,327,436 EXTENSIBLE AND RETRACTIBLE BEAM Albert C. Maier, Lakeside, Califl, assignor to The Ryan Aeronautical (10., San Diego, Calif. Filed Sept. 3, 1964, Ser. No. 394,235 4 Claims. (Cl. 52-111) This invention relates generally to an extensible and retractible beam and more particularly to a resilient beam which will retain sufiicient memory to return to its original position upon release after being retracted or furled.

It is especially important that the resilient ribs of parabolic antennae are capable of being furled or retracted into a minimum of space to facilitate packaging yet at the same time retain sufiicient resilience or memory for ready deployment when required; and it is accordingly the primary object of this invention to provide an improved extensible and retractible resilient beam for this and like purposes.

It is a further object of this invention to provide a resilient beam having improved means incorporated directly therein for retracting the beam.

Finally, it is an object to provide an extensible and retractible beam of the aforementioned character which is simple and convenient to use and which will give generally eflicient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully described in the specification, particularly pointed out in the claims, and illustrated in the drawing which forms a material part of this disclosure, and in which:

FIGURE 1 is a view of the resilient beam in fully extended position;

'FIGURE 2 is a view showing the beam partly retracted;

FIGURE 3 is a view showing the beam in a further retracted position;

FIGURE 4 is a view showing the beam fully retracted; and

FIGURE 5 is a top plan view showing the beam in the fully extended position.

With particular reference to FIGURES 1 and 5, I have shown a resilient elongated beam which is formed of spring stock of any suitable material. Since the beam is capable of being rolled on itself, it may be referred to as extensible and retractible. While not limited in its particular use, I have found that it is especially well adapted for use as a rib of a parabolic antenna. The inherent resiliency of the beam provides suflicient memory to return it to its original extended position upon release after it has been retracted or furled and when furled, it occupies a minimum of space for convenient packaging.

One end of beam 10 is attached as at 12 to any suitable support member 14. Beam 10 extends radially from the support and is slightly bowed as shown in FIGURE 1. The term support member 14 is represented herein as including a mere extension of the beam 10 and the hereinafter described motor 32 could be mounted on this extension. The free end 16 may, if desired, be provided with a small suitably rotatably mounted pulley 18. A guide means 20 is provided intermediate the ends of the beam. As here shown, the guide means consists of an aperture in the beam located approximately midway between the ends thereof. A grommet 22 of any suitable antifriction material such as nylon may be fixed in guide means 20.

A tension cable 24 has one end attached to beam 10 at point 26 which is closely adjacent the end 16. This cable is then threaded through the guide means 20 and looped back over the pulley 18. It is then passed through a suitable guide 28 in support 14 where the other end is attached to drum 30. Any suitable means such as motor 32 is operatively connected to drum 30 to rotate it in a direction to reel in cable 24.

The operation of my improved extensible and retract ible beam will be apparent from the above description when taken with the disclosure in the drawing. It is, of course, obvious that the beam 10 must be sufficiently flexible to be flexed by cable 24 when tension is applied thereto. Since the beam flexes first at the end 16, it may be desirable to build a slight taper into the beam as shown in FIGURE 5 to provide a flexibility gradient toward the outer end.

Assuming that the beam is in its extended position as shown in FIGURE 1, actuation of the motor 32 will rotate drum 30 causing cable 24 to be wound thereon. This will shorten the effective length of the cable and cause bending of the beam substantially as shown in FIGURE 2. Continued rotation of drum 30 will pull the cable through the grommet 22 so that the end 16 of the beam 10 will lie on the beam adjacent the grommet 22. Further shortening of the cable will result in rolling of the beam upon itself until the position shown in FIGURE 4 is reached when the beam will be in the fully retracted or furled condition. When used as the ribs of a parabolic antenna, a number of beams 10 radiate from the support 14 and the cables 24 for each beam will be connected to the same drum so that they may be furled and unfurled simultaneously.

It is understood that minor variation from the form of the invention herein may be made without departure from the spirit and scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. In combination:

an extensible and retractible elongated resilient beam having guide means intermediate the ends thereof; and

a flexible cable means one end of which is fixedly attached adjacent one end of said beam, extending over said guide and looped back over said one end for rolling said one end of said beam upon itself.

2. The structure of claim 1 in which said guide means is an aperture extending through said beam.

3. In combination:

an extensible and retractible elongated resilient beam having guide means intermediate the ends thereof;

a support means;

one end of said beam attached to said support;

a flexible cable means, one end of which is attached adjacent the other end of said beam, extending over said guide means and looped over said other end; and

means on said support for reeling in said cable means whereby the cable is shortened and the beam is rolled upon itself from said other end.

4. The structure of claim 3 in which said guide means is an aperture extending through said beam.

References Cited UNITED STATES PATENTS 2,097,707 11/1-937 Tichenor 51-110 X 2,179,365 11/1939 Williams 52110 2,276,935 3/1942 Como 52100 X 3,142,127 7/1964 Mason 4319 FRANK L. ABBOTT, Primary Examiner.

R. S. VERMUT, Assistant Examiner. 

1. IN COMBINATION: AN EXTENSIBLE AND RETRACTIBLE ELONGATED RESILIENT BEAM HAVING GUIDE MEANS INTERMEDIATE THE ENDS THEREOF; AND A FLEXIBLE CABLE MEANS ONE END OF WHICH IS FIXEDLY ATTACHED ADJACENT ONE END OF SAID BEAM, EXTENDING OVER SAID GUIDE AND LOOPED BACK OVER SAID ONE END FOR ROLLING SAID ONE END OF SAID BEAM UPON ITSELF. 